feat(data): session skills entity, repository, and migration

src/ClaudeDo.Data/Models/AppSettingsEntity.cs

@@ -27,4 +27,7 @@ public sealed class AppSettingsEntity
 
     // Max number of open tasks the daily prep ("Prime Claude") may place in MyDay.
     public int DailyPrepMaxTasks { get; set; } = 5;
+
+    // JSON array of session skill names applied by default to new tasks.
+    public string? SessionSkills { get; set; }
 }

src/ClaudeDo.Data/Models/ListConfigEntity.cs

@@ -7,6 +7,7 @@ public sealed class ListConfigEntity
     public string? SystemPrompt { get; set; }
     public string? AgentPath { get; set; }
     public int? MaxTurns { get; set; }
+    public string? SessionSkills { get; set; }
 
     // Navigation property
     public ListEntity List { get; set; } = null!;

src/ClaudeDo.Data/Models/SessionSkillEntity.cs

@@ -0,0 +1,11 @@
+namespace ClaudeDo.Data.Models;
+
+public sealed class SessionSkillEntity
+{
+    public required string Name { get; init; }
+    public required string SourceUrl { get; set; }
+    public required string PinnedRef { get; set; }
+    public required string Subpath { get; set; }
+    public required string Description { get; set; }
+    public required DateTimeOffset AddedAt { get; set; }
+}

src/ClaudeDo.Data/Models/TaskEntity.cs

@@ -45,6 +45,7 @@ public sealed class TaskEntity
     public bool IsMyDay { get; set; }
     public string? Notes { get; set; }
     public int SortOrder { get; set; }
+    public string? SessionSkills { get; set; }
 
     public string? ParentTaskId { get; set; }
     public string? PlanningSessionId { get; set; }